如何使用 Kotlin 通过数据绑定在 RecyclerView Adapter 中实现 onClick

Question

我使用数据绑定创建了一个 RecyclerView 适配器，我正在尝试处理此适配器内的 Click 事件，但我不知道具体如何操作。我找到了不同的主题，但仍无法解决我的问题。谢谢！我应该在哪里（在 Adapter class 内）实现 onClick 函数？

适配器Class

class RemovableContactsAdapter(val viewModel: GroupDetailsViewModel,val callback:GroupContactsCallback) : RecyclerView.Adapter<RemovableContactsViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RemovableContactsViewHolder {
    val binding: ViewDataBinding =
        DataBindingUtil.inflate(LayoutInflater.from(parent.context), viewType, parent, false)
    return RemovableContactsViewHolder(binding)
}

override fun onBindViewHolder(holder: RemovableContactsViewHolder, position: Int) {
    holder.bind(viewModel, callback, position)

}

override fun getItemCount(): Int {
    return viewModel.currentGroup.value?.contacts?.size ?: 0
}

override fun getItemViewType(position: Int): Int {
    return R.layout.removable_contact_layout
}
}

class RemovableContactsViewHolder(val binding: ViewDataBinding) :
RecyclerView.ViewHolder(binding.root) {

fun bind(viewModel: GroupDetailsViewModel, callback: GroupContactsCallback, position: Int) {
    binding.root.selected_contact_iv.apply {
        visibility = if (viewModel.currentGroup.value?.contacts!![position].selected) {
            View.VISIBLE
        } else {
            View.GONE
        }
    }
    binding.setVariable(BR.contact, viewModel.currentGroup.value?.contacts?.get(position))
    binding.setVariable(BR.callback, callback)
    binding.executePendingBindings()
   }
}

Fragment中的回调接口class:

interface GroupContactsCallback {
   fun selectContact(contact: ContactModel)
}

编辑

我更新了 RemovableContactsViewHolder 中的绑定函数，但仍然无法正常工作。

class RemovableContactsViewHolder(val binding: ViewDataBinding) :
RecyclerView.ViewHolder(binding.root) {

fun bind(viewModel: GroupDetailsViewModel, callback: GroupContactsCallback, position: Int) {
    itemView.setOnClickListener {
        viewModel.currentGroup.value?.contacts?.get(position)!!.selected = !viewModel.currentGroup.value?.contacts?.get(position)!!.selected
        callback.selectContact(viewModel.currentGroup.value?.contacts?.get(position)!!)
    }

    binding.root.selected_contact_iv.apply {
        visibility = if (viewModel.currentGroup.value?.contacts!![position].selected) {
            View.VISIBLE
        } else {
            View.GONE
        }
    }

    binding.setVariable(BR.contact, viewModel.currentGroup.value?.contacts?.get(position))
    binding.setVariable(BR.callback, callback)
    binding.executePendingBindings()
}

Answer 1

override fun onBindViewHolder(holder: RemovableContactsViewHolder, position: Int) {
holder.bind(viewModel, callback, position)

holder.binding.your_view_like_button.setOnClickListener {
// do something 
}
}

for example

  class AppointTimeSloatAdapter(
      private var mOptionList: List<String>,
      var context: Context,
      var appointmentDate: String,
  ) : RecyclerView.Adapter<AppointTimeSloatAdapter.ViewHolder>() {
      private var checkedRadioButton: CompoundButton? = null

      override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
          val viewProductCategoryBinding: AdapterAppointmentTimeSloteBinding =
              AdapterAppointmentTimeSloteBinding.inflate(
                  LayoutInflater.from(parent.context),
                  parent,
                  false
              )
          return ViewHolder(viewProductCategoryBinding)
      }


      override fun onBindViewHolder(holder: ViewHolder, position: Int) {
          val option = getItem(position)
          holder.binding.radioBtn.text = option.toString()

          holder.binding.radioBtn.setOnCheckedChangeListener(checkedChangeListener)
          if (holder.binding.radioBtn.isChecked) checkedRadioButton = holder.binding.radioBtn

          holder.binding.radioBtn.setOnClickListener {
              var intent = Intent(context, NewAppointmentActivity::class.java)
              intent.putExtra("time",holder.binding.radioBtn.text.toString())
              intent.putExtra("appointmentDate", appointmentDate)
              context.startActivity(intent)
          }


      }

      private val checkedChangeListener =
          CompoundButton.OnCheckedChangeListener { compoundButton, isChecked ->
              checkedRadioButton?.apply { setChecked(!isChecked) }
              checkedRadioButton = compoundButton.apply { setChecked(isChecked) }
          }

      fun updateList(list: ArrayList<String>) {
          mOptionList = list
          notifyDataSetChanged()
      }


      private fun getItem(index: Int): String {
          return mOptionList[index]
      }

      override fun getItemCount(): Int {
          return mOptionList.size
      }


      inner class ViewHolder(val binding: AdapterAppointmentTimeSloteBinding) :
          RecyclerView.ViewHolder(binding.root), View.OnClickListener {
          override fun onClick(v: View?) {
              ////
          }
      }

  }

Answer 2

应用以下方法。

在你的适配器中class

class RemovableContactsAdapter(val viewModel: GroupDetailsViewModel,val callback:GroupContactsCallback) : RecyclerView.Adapter<RemovableContactsViewHolder>() {
private var onClickListener: OnClickListener?=null
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RemovableContactsViewHolder {
    val binding: ViewDataBinding =
        DataBindingUtil.inflate(LayoutInflater.from(parent.context), viewType, parent, false)
    return RemovableContactsViewHolder(binding)
}

override fun onBindViewHolder(holder: RemovableContactsViewHolder, position: Int) {
    holder.bind(viewModel, callback, position)

holder.itemView.setOnClickListener {
            if(onClickListener!=null){
                onClickListener!!.onClick(position)
            }
        }

}

override fun getItemCount(): Int {
    return viewModel.currentGroup.value?.contacts?.size ?: 0
}

override fun getItemViewType(position: Int): Int {
    return R.layout.removable_contact_layout
}
}

class RemovableContactsViewHolder(val binding: ViewDataBinding) :
RecyclerView.ViewHolder(binding.root) {

fun bind(viewModel: GroupDetailsViewModel, callback: GroupContactsCallback, position: Int) {
    binding.root.selected_contact_iv.apply {
        visibility = if (viewModel.currentGroup.value?.contacts!![position].selected) {
            View.VISIBLE
        } else {
            View.GONE
        }
    }
    binding.setVariable(BR.contact, viewModel.currentGroup.value?.contacts?.get(position))
    binding.setVariable(BR.callback, callback)
    binding.executePendingBindings()
   }

 fun setOnClickListener(onClickListener: OnClickListener){
        this.onClickListener=onClickListener
    }

    interface OnClickListener{
        fun onClick(position: Int)
    }
}

在你Activity/Fragmentclass创建一个名为adapter的对象然后

val adapter=RemovableContactsAdapter(viewModel,callback)
adapter.setOnClickListener(object :SettingAdapter.OnClickListener{
            override fun onClick(position: Int){
                //position is your clicked view position
            }
        })

我已经在我的答案中修改了你的代码，继续吧，希望问题能得到解决。

Answer 3

在适配器内部处理点击不是一个好习惯。并且不要为此使用接口。请改用它。

class YourRecyclerViewAdapter(private val onSelect: (YourDataType?) -> Unit) : RecyclerView.Adapter<YourRecyclerViewAdapter.YourViewHolder>() {

    override fun onBindViewHolder(holder: YourViewHolder, position: Int) {
        holder.bind(getItem(position), onSelect)
    }

    class ViewHolder(private val binding: YourViewBinding) : RecyclerView.ViewHolder(binding.root) {

        fun bind(yourDataType: YourDataType?, onSelect: (YourDataType?) -> Unit) {

           // bind your view here
           binding.root.setOnClickListener {
               onSelect(yourDataType)
           }
        }
    }
}

在你的Fragment/Activity

// Set this adapter to your recycler view
val adapter = YourRecyclerViewAdapter { yourDataType-> 
    // Handle click here
}

如何使用 Kotlin 通过数据绑定在 RecyclerView Adapter 中实现 onClick

How to implement onClick in RecyclerView Adapter with databinding using Kotlin

android

adapter

kotlin

android-recyclerview

android-databinding